Dinosaur Reptile Skin
so I'm not an expert on blender, just someone who messes with it occasionally, but i think a good way to do this would be to use a normal map.

Just in case you don't know what that is, it's like your standard image texture, but it tells the light how to interact with as if it's 3d. This can make an object look like is has more geometry than it actually does. here are a couple of examples of how they look


https://i0.wp.com/unitycoder.com/blog/wp-content/uploads/2013/07/poormans_normal_specular_map_generator_unity3d_big.jpg


http://wiki.polycount.com/w/images/thumb/c/c9/Normalmap_stairs.jpg/1406px-Normalmap_stairs.jpg

So what you do is you pair a normal map with a standard color texture map and boom. it can look pretty nice. There are plenty of tutorials on youtube that show you how to use all kinds of other texture maps than just your color ones. 

They aren't usually used with a high poly sculpt, but i bet with a little searching and adaptation of standard stuff you can do it. 

anyway that's my piece of advise, again I'm no professional but maybe this will help.